mesa: Add new ir_unop_any() expression operation.

The previous any() implementation would generate arg0.x || arg0.y ||
arg0.z.  Having an expression operation for this makes it easy for the
backend to generate something easier (DPn + SNE for 915 FS, .any
predication on 965 VS)

src/glsl/ir_validate.cpp

@@ -223,6 +223,11 @@ ir_validate::visit_leave(ir_expression *ir)
       assert(ir->type->base_type == GLSL_TYPE_FLOAT);
       break;
 
+   case ir_unop_any:
+      assert(ir->operands[0]->type->base_type == GLSL_TYPE_BOOL);
+      assert(ir->type == glsl_type::bool_type);
+      break;
+
    case ir_unop_trunc:
    case ir_unop_ceil:
    case ir_unop_floor: